Custom HID issue : offset in hid data

Gabriel T · ‎2020-12-16

Hi,

I am working on Nucleo STM32H743ZI

I am using a 64byte size custom usb hid when I send my data frames i get an offset of 6 zeros as shown here :

Any ideas where it comes from ?

Regards,

Gabriel

Ons KOOLI · ‎2020-12-16

Hi GTéta.1,

When working with DMA in H7 products you should pay attention on where you put your code.

By default in the linker file, you can see that the RAM starts from 0x20000000 address and ends in 0x2001FFFF which is the DTCM region.

Unfortunately, the DTCM is not accessible by DMA. Therefore, When working with DMA, you should put your code in an accessible region by DMA (for example AXI SRAM).

Please refer to the RM0433 for more details.

Best Regards,

Ons.

View solution in original post

Gabriel T · ‎2020-12-16

Update :

The problem disappear if i disable usb dma :

Gabriel T · ‎2020-12-16

I would like to use DMA, anyparameter I am missing for the USB DMA ?

Ons KOOLI · ‎2020-12-16

Hi GTéta.1,

When working with DMA in H7 products you should pay attention on where you put your code.

By default in the linker file, you can see that the RAM starts from 0x20000000 address and ends in 0x2001FFFF which is the DTCM region.

Unfortunately, the DTCM is not accessible by DMA. Therefore, When working with DMA, you should put your code in an accessible region by DMA (for example AXI SRAM).

Please refer to the RM0433 for more details.

Best Regards,

Ons.

Ons KOOLI · ‎2020-12-17

Hi GTéta.1,

In case your problem is solved, please mark this question as answered by selecting the best answer.

Best Regards,

Ons.